seat back problem

I have a 2005 Lesabre Custom that I am almost ashamed to even ask this question but it is really getting annoying.
There is something in the drivers seat back that is moving around and is very noticable when stopping or starting.
Is there some way to get into the seat back to find out what is going on in there?
Thanks for any help or suggestions.

i built seat for lear for 20 years most seat back were held together in the area were your butt sits with zippers or what is called a j- strap or j-and arrow if its jstrap to j-strap use a blunt object to pry the j apart then start sliding it along to seperate them if its j and arrow the arrow rolles then snap into the j it comes apart by un rolling the arrow part if its zipper take a pick slide it in to the part of the zipper were the little handle you pull on when you zip your coat up then pull the zipper should slide